Problem with focal mechanism ploter

Q&A PyGMT Q&A
1

Hello,

I am trying to plot a set of focal mechanisms over a map; however, I get an error that I have not been able to solve.

I have tried loading a dictionary or a file in the “spec” option and it does not work. Even I have tried with the same example on the pygmt gallery.

This is a test example that generates an error:

focal_mechanism = dict(strike=330, dip=30, rake=90, magnitude=3)
fig.meca(focal_mechanism, scale=“1c”, longitude=-124.3, latitude=48.1, depth=12.0)

This is the error message I am getting:
"
Traceback (most recent call last):
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/IPython/core/interactiveshell.py”, line 3378, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File “”, line 1, in
fig.meca(‘test_meca.txt’, convention = ‘aki’, scale=“1.0c”)
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/helpers/decorators.py”, line 598, in new_module
return module_func(*args, **kwargs)
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/helpers/decorators.py”, line 738, in new_module
return module_func(*args, **kwargs)
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/src/meca.py”, line 339, in meca
lib.call_module(module=“meca”, args=build_arg_string(kwargs, infile=fname))
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/clib/session.py”, line 530, in call_module
raise GMTCLibError(
pygmt.exceptions.GMTCLibError: Module ‘meca’ failed with status code 45:
"

Thank you very much for your help.

Best wishes,

Camilo

2

Hello @cpinilla,

Welcome to the GMT forum :slightly_smiling_face:!

As your code example is incomplete, it is a bit difficult to say what is going wrong in detail.
Maybe you can also provide your input file “test_meca.txt”?

In your code example, arguments for the region, projection, and frame parameters are missing.
Beside specifying those within pygmt.Figure.meca you can also use pygmt.Figure.basemap (pygmt.Figure.basemap — PyGMT) or pygmt.Figure.coast (pygmt.Figure.coast — PyGMT, see also gallery example Focal mechanisms — PyGMT).

Code example:

import pygmt

focal_mechanism = dict(strike=330, dip=30, rake=90, magnitude=3)

# Create figure object 
fig = pygmt.Figure()

# Plot beachball
fig.meca(
    region=[-128, -122, 46, 50],  # lon_min_E, lon_max_E, lat_min_N, lat_max_N
    projection="M10c",  # Mercator projection with width of 10 centimeters
    frame=True,  # Use default frame settings
    spec=focal_mechanism,
    scale="1c",
    longitude=-124.3,
    latitude=48.1,
    depth=12.0,
)

# Show and save figure
fig.show()
#  fig.savefig(fname="plot_meca_dict.png")

Output figure:

plot_meca_dict
plot_meca_dict1350×1251 6.27 KB

3

Hi Yvone,

Thank you for replying. I have already set up the map, with all the features I want. I just want to add the focal mechanism.

By running your code, I have the same error as before. I do not know if I should include some library or flag during the cmake compilation of GMT, considering some modifications to my virtual environment … I do not know. Here is the error message.

Traceback (most recent call last):
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/IPython/core/interactiveshell.py”, line 3378, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File “”, line 13, in
fig.meca(
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/helpers/decorators.py”, line 598, in new_module
return module_func(*args, **kwargs)
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/helpers/decorators.py”, line 738, in new_module
return module_func(*args, **kwargs)
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/src/meca.py”, line 339, in meca
lib.call_module(module=“meca”, args=build_arg_string(kwargs, infile=fname))
File “/home/camilo/PhD/Simulations/codes/venv/lib/python3.10/site-packages/pygmt/clib/session.py”, line 530, in call_module
raise GMTCLibError(
pygmt.exceptions.GMTCLibError: Module ‘meca’ failed with status code 45: